1. Statement of the Technical Field
The present invention relates to the field of enterprise computing and more particularly to the securing of cached data in an enterprise application environment.
2. Description of the Related Art
As business organizations deploy important business applications over the Internet, challenges arise in the form of processing delays and network latencies. Specifically, the placement of application content in a centralized server can compel users' requests to traverse multiple congested networks in an attempt to effectively interact with the application. As a result, this centralized approach to deploying applications on the Internet can hinder the attainment of scalability, reliability and performance levels that are considered “mission-critical” in the deployment of a business application.
In consequence of the inherent deficiencies of the centralized approach, there has been a recent trend to move more application processing functions to the edge of the network. In lay terms, the “edge” of the network refers to that portion of a publicly accessible network which is disposed communicatively closer to the end-user. While the positioning of servers and other network devices at the edge of the network can bear direct relation to the geographical positioning of the end-users, in some cases, the positioning of servers at the edge of the network can bear closer relation to the available communications bandwidth and the performance of network components linking end-users to the servers.
E-Business applications can experience dramatic performance and scalability improvements by off-loading applications from a centralized portion of an Intranet to the edge of the publicly accessible network. Application off-loading can be achieved by distributing application data to the edge of the network. In consequence, the load experienced by the centralized data servers can be reduced as can associated network traffic. One common method of off-loading data to the edge of the network includes query caching.
Query caching involves the dynamic storage of query results based upon query rules which determine when the results of a query ought to be stored in a local data store at the edge of the network. The cached data can be used to satisfy subsequent queries without retrieving the requested data from the back-end data store. Of course, where the requested data cannot be satisfied by the cache, the back-end data store can satisfy the query.
Notably, where the back-end data store in the Intranet includes sensitive data, security measures can be easily undertaken, including for instance, data encryption. In this way, unauthorized viewers cannot access the secured data without having prior knowledge of a decryption key. Furthermore, as the back-end data store is located within the Intranet, access to the application data, itself, can be regulated with some ease. Yet, the same does not hold true for application data which has been removed outside of the Intranet into what has been commonly referred to as the “demilitarized zone”.
Specifically, while application data can be secured at the application level in a back-end data store, once the application data has been cached at the edge of the network in the demilitarized zone, the cached data can become vulnerable to unauthorized viewers. In particular, conventional query caches provide no mechanism for securing cached data from unauthorized viewers. Moreover, as the query cache resides in the demilitarized zone, access to the cache cannot be easily regulated. Thus, a serious security concern can arise where an enterprise application is to be deployed using an edge processing architecture.